Refrigerating apparatuses which perform a refrigerating cycle are conventionally known and widely utilized as an air-conditioning machine for performing air-cooling/heating in a room or a cooling machine such as a refrigerator for storing foods. Among the refrigerating apparatuses, there is a refrigerating apparatus which performs air-conditioning and cold-storage/freezing as disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2001-280749. This type of refrigerating apparatus comprises a plurality of application-side heat exchangers, e.g., for air-conditioning channel and cold-storage/freezing channel (air-conditioning heat exchanger, cold-storage heat exchanger, freezing heat exchanger and the like), and is installed at a convenience store and the like. By installing one refrigerating apparatus, air-conditioning within a store and air-cooling for showcases can be performed.
In accordance with this type of the refrigerating apparatus, in order to widely vary the capacity of a compressor depending on operational states of the plurality of application-side heat exchangers, a compression mechanism is configured by two compressors in some cases. For example, the compression mechanism may be configured by connecting an inverter compressor for an inverter control in parallel to a non-inverter compressor for an on-off control.
It is desired in the above-described type of the refrigerating apparatus that various operation modes are realized such as an operation of only air-cooling or air-heating, an operation of only cold-storage/freezing and an operation in which air-cooling/heating is combined with cold-storage/freezing. When two compression mechanisms are simply connected in parallel, this configuration cannot sufficiently correspond to a large number of operation modes. When one compressor is dedicated to air-conditioning and the other compressor is dedicated to cold-storage/freezing, if one of the compressors is broken, operation cannot be continued. Especially when the compressor for cold-storage/freezing channel is broken, influences may exert on quality of products such as frozen foods. Thus, this becomes a more serious problem as compared to the case in which the compressor for the air-conditioning channel is broken.
Then, the applicant of the present application has suggested a technique in which in this type of the refrigerating apparatus, a compression mechanism is configured by combining three compressors, and compressors to be used for the air-conditioning side and the cold-storage/freezing side can be appropriately selected from these three compressors (e.g., Japanese Patent Application No. 2001-192702). This refrigerating apparatus is configured so that three compressors can be freely combined in accordance with various patterns and then operated, such that these three compressors are used for the cold-storage/freezing side, two compressors are used for the cold-storage/freezing side and one compressor is used for the air-conditioning side or operation is performed by one compressor, and so that even if one compressor is broken, the operation can be continued by other compressors.
Problems to be Solved
When three compressors are used, however the structure of the apparatus must be complicated, e.g., a mechanism for switching a refrigerant flow at suction and discharge sides of pipes is required. If the switching mechanism is complicated, control thereof is also complicated. For this reason, especially when a relatively compact system is considered in a refrigerating apparatus which performs air-cooling/heating and cold-storage/freezing, desirably, while the structure is simplified by configuring a compression mechanism with two compressors, operation patterns are increased.
The present invention was developed in view of such points of view and an object of the present invention is to, in a refrigerating apparatus comprising a plurality of application-side heat exchangers for air-conditioning and for cold-storage/freezing, increase operation patterns when a compression mechanism is configured by two compressors and thus to continue operation even if one of the compressors is broken.